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SubjectRe: [PATCH] PCI: tegra: Use PCI_CONF1_EXT_ADDRESS() macro
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On 28/09/2022 13:19, Pali Rohár wrote:
> Simplify pci-tegra.c driver code and use new PCI_CONF1_EXT_ADDRESS() macro
> for accessing PCI config space.
>
> Signed-off-by: Pali Rohár <pali@kernel.org>
> ---
> Please look also at this related patch:
> https://patchwork.kernel.org/project/linux-pci/patch/20220911113216.14892-1-pali@kernel.org/
> ---
> drivers/pci/controller/pci-tegra.c | 11 +++--------
> 1 file changed, 3 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c
> index 5df90d183526..c9924e75e597 100644
> --- a/drivers/pci/controller/pci-tegra.c
> +++ b/drivers/pci/controller/pci-tegra.c
> @@ -417,13 +417,6 @@ static inline u32 pads_readl(struct tegra_pcie *pcie, unsigned long offset)
> * address (access to which generates correct config transaction) falls in
> * this 4 KiB region.
> */
> -static unsigned int tegra_pcie_conf_offset(u8 bus, unsigned int devfn,
> - unsigned int where)
> -{
> - return ((where & 0xf00) << 16) | (bus << 16) | (PCI_SLOT(devfn) << 11) |
> - (PCI_FUNC(devfn) << 8) | (where & 0xff);
> -}
> -
> static void __iomem *tegra_pcie_map_bus(struct pci_bus *bus,
> unsigned int devfn,
> int where)
> @@ -445,7 +438,9 @@ static void __iomem *tegra_pcie_map_bus(struct pci_bus *bus,
> unsigned int offset;
> u32 base;
>
> - offset = tegra_pcie_conf_offset(bus->number, devfn, where);
> + offset = PCI_CONF1_EXT_ADDRESS(bus->number, PCI_SLOT(devfn),
> + PCI_FUNC(devfn), where) &
> + ~PCI_CONF1_ENABLE;
>
> /* move 4 KiB window to offset within the FPCI region */
> base = 0xfe100000 + ((offset & ~(SZ_4K - 1)) >> 8);


Our PCIe test on Tegra124 Jetson TK1 is currently failing on -next and
bisect points to this commit. Looking at bit closer, the problem appears
to be the PCI_CONF1_REG_MASK which has a value of 0xfc. Before this
patch was applied a mask of 0xff was applied to the lower 8-bits of
'where' and now it is 0xfc. So this does not work for Tegra as it is.

Let me know if you have any thoughts?

Jon

--
nvpublic

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